The present disclosure relates generally to excitation of windings in an electromagnetic machine system, and relates more particularly to injecting electrical current into a stator such that a flux distribution of a stator magnetic field is changed in response to the injected electrical current to induce electrical excitation currents in exciter circuitry of a rotor.
A vast array of electromagnetic machine systems such as electric motors and electric generators are well-known and widely used. Most such systems include a stationary component referred to as a stator and a movable component referred to as a rotor. One or both of the stator and the rotor will typically include permanent magnets or electro-magnets.
Electromagnetic interaction between the stator and rotor induces relative motion between the two or generates electrical current, all in a well-known manner. For so-called synchronous machines it is generally necessary to electrically excite windings in the rotor so as to produce a rotor magnetic field that is either induced to rotate by a rotating magnetic field in the stator, in the case of a synchronous motor, or induces a magnetic field in the stator in the case of a generator. In either instance, a dedicated electrical exciter separate from the rotor itself is typically used to produce electrical current that excites the rotor windings. Existing systems have a number of shortcomings at least in certain applications.